Police are appealing for witnesses after it is believed an Eddie Stobart HGV collided with a pedestrian, previously thought to have been driving a VW Caddy panel van.
Police and emergency services were called to the A38 under a bridge for the M5 near Droitwich shortly before 4.30pm on Monday (13 August).
It is thought an altercation may have begun on the southbound M5 carriageway between junction 4a and junction 5.
A man in his 60s suffered chest, pelvic and head injuries and was taken to the Queen Elizabeth Hospital in Birmingham but subsequently died. His next of kin has been informed and the family are being supported by specially trained officers.
A man in his 50s has been arrested on suspicion of murder. He remains in police custody at this time.
Detective Inspector John Cashion said: "A thorough investigation has been launched to establish the circumstances behind the collision.
"Enquiries are ongoing and we would encourage anyone who saw the vehicles and the manner in which they were being driven on the M5 or the A38 prior to the incident to come forward.
"We are also keen to speak to anyone who witnessed the incident or who has dashcam footage of the moments leading up to the collision.
"Our thoughts remain with the man's family at this difficult time."
A spokesman for Eddie Stobart said: "We are aware that one of our drivers was involved in a serious collision and we are working closely with the relevant authorities to support with their investigations."
Anyone with any information or dashcam footage of the incident is asked to call West Mercia Police on 101 or Crimestoppers anonymously on 0800 555 111 quoting incident number 518S of August 13.